A conventional pocket hole jig for drilling wooden workpieces is disclosed in Taiwan Patent No. M297278 and contains a guiding column with a body, and the body includes a aligning face defined on a bottom thereof so as to contact with the wooden workpieces in drilling process, and the body also includes a tilted face defined on a front end thereof and a recess, wherein the recess tilts toward the aligning face from the tilted face, and the tilted face has a guide sleeve configured to guide a driller toward the wooden workpieces via the recess, and the body further includes an abutting face formed on a rear end thereof and perpendicular to the aligning face, such that when the abutting face is in alignment with an edge of a wooden workpiece, a central line of the driller aligns with a center of a thickness of the wooden workpiece by means of the tilted face. The abutting face has an orifice extending toward the body so as to house an extension block, thus changing a horizontal distance between the guiding column and the edge of the wooden workpiece. The extension block has a coupling post adjacent to the abutting face, when the extension block is in connection with the body, the coupling post is accommodated in the orifice of the body.
However, the conventional pocket hole jig is applicable for screws of various sizes by using a plurality of extension blocks, thus causing using inconvenience.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.